(!) We use cookies to give you the best possible experience on our website. By continuing to browse this site, you give consent for cookies to be used.
For more details, please read our
cookie policy (!)

Using the PacBio, which can read longer stretches of DNA in their entirety, along with the developed NB-LRR gene workflow ‘RenSeq’ (Resistance gene enrichment sequencing), the data not only targets R genes, but also the important regulatory regions of DNA - promoters and terminators that signal when to start making a protein and when to stop.

Each plant typically carries hundreds of potential R gene sequences, encoding NB-LRR proteins, identified by the presence of specific sequence motifs. R genes are often part of families of closely related sequences.

Dr Matt Clark, Head of Technology Development at EI and lead author of the study, said: ‘Wild relatives of crops contain a huge repertoire of novel genes that could be used to breed more resistant varieties that need less pesticide treatments. When it comes to identifying key genes it can be very difficult for researchers to find the exact resistance gene due to the sheer similarity of their DNA sequences. Typical sequencing methods use short reads for example, from the Illumina HiSeq, but these are often too short to prise similar genes apart.’

‘RenSeq diverges from normal DNA sequencing on the PacBio by focusing the sequencing effort on a specific gene family i.e. R-genes stated Clark. 'In this study, by optimising multiple steps in the library construction, we can identify the protein-coding sequences and the neighbouring regulatory regions; indeed in many cases we can reconstruct the entire DNA region even if it contains many similar genes which normally are too hard to tell apart. This means we can identify the exact gene that confers resistance to a certain infection, and used in breeding programmes.’

Dr Ingo Hein, principal investigator at the James Hutton Institute, added: ‘R genes can control diverse plant diseases including major threats to global crop production. The ability to capture and sequence long genomic DNA fragments that contain full-length R genes enables the rapid identification of novel, functional resistance genes from wild species. These genes, if introgressed into new cultivars via breeding or alternative routes, could significantly reduce the dependency on pesticides for crop production.’